Speed indicators



Sept. 27, 1955 E. G. STACK SPEED INDICATORS 5 Sheets-Sheet 1 Filed Jan. I5, 1950 Q Q %Em I /A/ VE' N TOR Sept. 27, 1955 E. G. STACK SPEED INDICATORS 5 Sheets-Sheet Filed Jan. 3 1950 /NVENTOR lnmlguu IIuTFiImm lgnm Sept. 27, 1955 E. G. STACK SPEED INDICATORS 5 Sheets-Sheet 3 Filed Jan. 5, 1950 /N VEN TOR ga i 3% II M RTW Q Sept. 27, 1955 E. G. STACK SPEED INDICATORS 5 Sheets-Sheet 4 Filed Jan. 3, 1950 M/VEN TOR Sept. 27, 1955 E. G. STACK 2,719,194

SPEED INDICATORS 5 Sheets-Sheet 5 Filed Jan. 3, 1950 Fi A.

M/VEN TOR United States Patent SPEED INDICATORS Emmet G. Stack, Portland, Orcg.

Application January 3, 1950, Serial No. 136,529

8 Claims. (Cl. 200-80) This application is a continuation'in-part of an abandoned application for a Speed Indicator, filed by me on September 23, 1949, Ser. No. 117,457, which this supersedes.

My invention relates to. a method and apparatus for indicating to the public the speed at which. a vehicle is moving at the instant.

The principal object of my invention is to deter, as far as possible, operators of automobiles and trucks from driving at excessive or unlawful speeds by informing the public as to the speed at which they. are moving.

Another object is to make any observer of a moving vehicle a competent judge of its speed and hence an indisputable witness by permitting him to read at a glance the speed at which a vehicle is approaching or receding.

A further object is to keep a driver informed as to what the driver in front of him is doing, that is, whether he is slowing down or speeding up, and how much.

A still further object is to inform a driver how fast an approaching vehicle is travelling so that he may determine whether it is safe to pull out to pass a vehicle in front of him.

How the above is brought about is set forth in this specification and in the accompanying drawings in which Fig. 1 is a longitudinal vertical section of a speed-indicator operating device of the spring-operated flyball type; Fig. 2 is a transverse vertical section on the line 2--2 of Fig. 1; Fig. 3 is an end view of Fig. 1; Fig. 4 is a longitudinal vertical section of a speed-indicator operating device of the direct lift type; Fig. 5 is a vertical section on the line 55 of Fig. 4; Fig. 6 is a diagram of a hook-up with the speed-indicator operating device drive taken off adjacent the auto drive shaft; Fig. 7 is a diagram of a hook-up with the speed-indicator operating device drive taken off adjacent the speedometer; Fig. 8 is a plan view of a right angle gear drive; Fig. 9 is a longitudinal vertical section of a speed-indicator operating device operated by air pressure; Fig. 10 shows the switch opposite to the one shown in Fig. 9; Fig. 11 is an end view of Fig. 9; Fig. 12 is a transverse vertical section on the line 12-12 of Fig. 9; Fig. 13 is a plan diagram showing the relative relation of the opposed switches, lamps, and wiring; Fig. 14 is a lamp elevation; Fig. 15 shows a vertical section of a ball type switch contactor; Fig. 16 shows a vertical section of a wiper type of switch contactor.

Thruout the drawings andthe specification similar numerals refer to similar parts.

All automobiles and trucks are provided with speedometers which indicate the speed at which the vehicle is moving. The speedometer is connected to the vehicles drive shaft rearward of the clutch, or its equivalent, thru the agency of gearing and flexible shafting My speedindicator operating device may be similarly connected and driven, or the hook-up may be similar to that employed to connect taxi-meters to and drive them from the speedometer shaft. Figs. 6-and 7 show two hook-up diagrams in which the numeralL indicates the centerline. of-the 2,719,194 Patented Sept. 27, 1955 ice vehicle drive shaft; 2, the centerline of the flexible shaft to the speedometer 3; 4, the standard right angle gear drive usually employed to drive a taxi-meter but which I can use to drive my speed-indicator operating device; 5, the flexible shaft centerline from the'meter drive to the speed-indicator operating device; and A, the speedindicator operating device. It is apparent from a perusal of Figs. 6 and 7, that the standard right angle gear drive 4 may be used at both the points indicated and so permit the taxi-meter to be included in the hook-up.

In this application the means shown to operate the speed-indicator operating means by air pressure is a blower of the positive type commonly known as the Root blower.

Another equivalent shown is the fly-ball governor operated speed-indicator operating device which functions perfectly at speedometer speeds.

The latter speed-indicator operating device has a hollow cylindrical shell 6 provided with a closed end wall 7 from which a boss 8 extends. This boss 8 has its end portion 9 threaded for the reception of the swivel nut 10 formed to engage the annular collar 11 on the tail piece 12 compressed onto the end of the flexible shaft casing 13 which surrounds the flexible drive shaft 14. Both the end wall 7 and the boss 8 are bored for the reception of the bushing 15 which forms one of the bearings within which is journalled the shaft 16 the opposite end of which is journalled in the bearing provided by the bushing 17 carried by the end piece 18 threaded into the end wall 19 of the cylindrical shell 6. This end piece 18 is provided with an annular flange 20 adapted to be brought into intimate contact with the end wall 19 to fix its position thereagainst. The end piece 18 is also provided with a rectangular end portion 21 counterbored in alignment with the shaft 16 to receive the self-aligning ball bearing 22. The inner race (not shown) of the bearing 22' is mounted on the pin 23 slidable in the counterbore 24 provided for it in the adjacent end of the shaft 16. The pin 23 is provided with a collar 25 against which the inner race bears. The outer race 26 of the bearing 22 is mounted in a cylindrical shell 27 whose outer periphery 28 is convexly formed so that the shell 27 may adjust itself within the counterbore 29 in the end portion 21. This cylindrical shell 27 is provided with an extension 30 formed with a slotted end 31 for the reception of the switch-operating lever 32 to which it is hingedly connected by the hinge pin 33. This lever 32 has a hub portion 34 whose ends are milled to receive the conical ends of the pivot screws 35 threaded into the side walls of the end portion 21. The lever 32 is adapted to be oscillated on its pivot pin screws 35 within the guide slots 36 provided for it in the top and bottom walls of the end portion 21, and the shell 27 carrying the outer race 26 of the bearing 22 is free to adjust itself to the oscillation of said lever 32. The oscillation of said lever 32 is effected by the longitudinal movement of the collared pin 23 as it is moved back and forth within its counterbore 24 by the hub 37, slidably mounted on the shaft 16, to which said collared pin 23 is connected by the pin 38 which passes thru said hub 37, pin 23, and slot 39 formed in the shaft 16. This slot 39 serves as a confining guide for the pin 38. Also mounted on the shaft 16 is another hub 40 which is secured to said shaft by the set screw 41. On degree centers the periphery of the hubs 37 and 40 are milled for the reception of the ends of the flat springs 42 which are secured to the hubs by the screws 43. Midway their ends weights 44 are secured to the flat springs 42 by the screws 45. When the shaft 16 is rotated centrifugal force causes the weights 44 to move outwardly bowing the springs 42. As the springs 42 bow outthey cause the slidable hub 37 to move toward the in the shaft keyway 49 thereof. The flexible drive shaft 14 is kept in driving position when the annular collar 11 on the tail piece 12 is clamped against the end of the boss 8 by the swivel nut 10.

In the design of the speed-indicator operating device now being described the arms of the lever 32 were made in the ratio of 1:16 with the upper portion 50 having a radial length of 4.5" and the lower portion 51 a length of 0.28125. The length of the chord 52 traversed by the upper portion 50 of the lever 32, with a vehicle speed range of from O to 60 miles per hour, was made 4.5"

long. Therefore, since the lever arms are proportional the chords must be proportional. If the chord 52 is then 4.5" long the maximum movement of the hub 37 must be 0.28125.

Centrifugal force varies as the square of the speed hence the outward movement of the weights 44 and the longitudinal movement of the hub 37 will vary as the square of the speed. With a vehicle speed of miles per hour and a speedometer speed of 250 R. P. M., the square of 250 will be 62,500. At 60 miles per hour and a speedometer speed of 1000 R. P. M., the square of 1000 will be 1,000,000, or 16 times as much as 62,500. If at 60 miles per hour the upper portion 50 of the lever 32 traverses a chord 52 4.5 long it will move of 4.5" or 0.28125" when the vehicle is travelling 15 miles per hour and the hub 37 will move of 0.28125" or 0.01883". A radial line thru a point 0.28125 from the zero point on the chord 52 will fix the location of the radial face of the segment 53 of conducting material indicating a vehicle speed of 15 miles per hour. The radial faces of segments indicating other ranges of vehicle speed may be similarly located. The formula by which the distance 0.28125" is derived follows: 250 4.5/1,000,000 equals 0.28125.

Figs. 1, 9, and 13, show four segments 53 of conducting material separated with or without insulating material therebetween which indicate the following vehicle speeds: to 30 miles, 30 to 40 miles, 40 to 50 miles, and 50 to 60 miles, while Figs. 10 and 13 show five segments 53 of conducting material separated by five segments 54 of insulating material. indicated by the segments 53 of conducting material are: 15 to 20 miles, to miles, to miles, to miles, and to miles, while the segments 54 of insulating material indicate the following ranges of vehicle speed: 0 to 15 miles, 20 to 25 miles, 30 to 35 miles, 40

to 45 miles, and 50 to 55 miles. To each segment 53 of conducting material is secured a terminal stud 55 provided with clamp nuts 56. So far I have glued the insulating and conducting segments to the switch bases 57 which are secured to the ears 58 on the upper wall 59 of the end portion 21 by the screws 60. These switch bases and the insulating segments have been made of Micarta. It is apparent that under mass production the segments and base may be moulded into a unit by using a suitable insulating plastic. The segments 53 of conducting material are best made of brass and preferably silver plated so as to always provide the best conducting qualities under a light contact.

Figs. 9, 11, and 15, show the contact made by the balls 61 preferably made of brass and silver plated which are positioned in inclined guideways 62 secured to the upper end of the lever 32. The balls 61 are free to roll and hence to adjust themselves to a rolling contact against the segments 53 and 54 with which they come in contact. Fig. 15, shows the contacting ball 61 backed up by The five ranges of vehicle speed i another ball 61A which helps to eliminate any tendency of the balls to dance.

Figs. 1, 3, 13, and 16, show the use of a Wiper contactor 63 made of thin spring brass silver plated. The contacting end is creased at 64 to stiffen said end 63A and to provide a sharp contacting face 65. The thin brass spring stock provides an almost frictionless contact and can easily be adjusted for touch or for alignment with opposite radial segment edges or faces as at 66.

As the balls 61 shown in Figs. 9, 11, and 15, or the wiper contactor 63 shown in Figs. 1, 3, l3, and 16, are moved over the segments 53 and 54 by the lever 32, electric circuits, fed by any source of supply such as the vehicles battery and/or generator, are opened and closed in accordance with the speed a vehicle is moving. In the circuits are lamps so placed as to be visible to the public and to designate to them the speed at which the vehicle is moving. Although many arrangements of these lamps may be had a simple, fool-proof, and preferred arrangement B is shown in Fig. 13, and described herein.

A group of lamps 67 of one color, and of a color different from the others, are arranged to form a ring or enclosure 68 around a central lamp 69. Outside the ring 68 and to the left is positioned the lamp above, the lamp 71; to the right, the lamp 72, and below, the lamp 73. It will be noted that this arrangement separates and spaces the various lamps relative to one another and to the ring 68 so that it is impossible to confuse the average observer as to their position although he may have no idea what they signify.

The lamps 67 which form the ring or enclosure 68, or a single neon lamp if that type is used, are always lighted. The arrangement herein set forth begins to function as soon as a vehicle speed of 15 miles per hour is reached, at which time the central lamp 69 lights up and remains lighted until a speed of 20 miles per hour is reached whereupon lamp 69 goes out and lamp '70 lights up. When the vehicle reaches a speed of 25 miles per hour lamp 69 lights up again and it and lamp 70 remain lighted until a speed of 30 miles per hour is attained whereupon both go out and lamp 71 lights up. At 35 miles lamp 69 lights up again. At 40 miles lamp 69 and 71. both go out and lamp 72 lights up. At 45 miles lamp 69 comes on and at 50 miles it and lamp 72 go out and lamp 73 lights up. At 55 miles lamp 69 comes on again and burns with lamp 73 as long as the vehicle speed remains at 55 miles or over, 55 miles being the legal limit in this State. This legal limit may be audibly announced to the public too by connecting the terminal stud 74 shown in Figs. 1 and 13, to the vehicles horn or the relay therefor. From a perusal of the above figures it is apparent that this terminal stud 74 may be positioned at any other point desired for contact with the lever 32 to close the horn circuit.

Fig. 13, shows the wiring diagram which will be understandable to anyone skilled in the art without detailed description. In Fig. 13, the square numbered 75 indicates the vehicles horn or its relay. The numerals encircled refer to vehicle speeds.

The lamps used with my device are made by many firms, and are of various designs, and are used for many purposes. A lamp, as 73, embraces a frame, a globe socket, a globe, a prism, and a clamp nut. Fig. 14 shows a standard design. A lamp is mounted by inserting the lamp frame 76 in a hole 77 provided for it in any desired base as a plate 78 where it is held in place by the clamp nut 79. Most lamps of this design are now made so that the prism 80 can be removed to replace a glove (not shown) without disturbing the mounting.

Instead of the speed indicating means, or lamp arrangement B, being mounted on a plate base for the front, rear, or top of a vehicle, it may be incorporated in the radiator grille, in the trunk lid, or in many other suitable places from where it may be observed whether the vehicle is approachingor receding. When the speed indicating means B are used both in the front and rear of a vehicle the lamp on the left should be wired to indicate the same speed. The lamp arrangement is so simple no one can be confused for all. he needs to remember is whether there were one or two lamps burning and what their relation was to the enclosing ring 68 to be a competent witness. The speed-indicator operating means A may be placed in any convenient place in the vehicle from where it may be driven.

In order to make lamp 69 burn when the vehicle reaches a speed of miles per hour, or lamp 70 burn when it reaches a speed of miles per hour, or both lamps burn when a speed of miles: per hour is reached, the speedindicator operating means A must be calibrated with the speedometer if that coincides with a master speedometer or tachometer. In the instant case the calibration is effected by the coil extension spring 81 which is secured to the lever 32 and to an adjustable take-up screw 82 provided with a nut 83.

For lack of space, Fig. 1 does not show the true length of the spring 81 which has 46 coils /8 O. D. of 0.024" wire. The weights 44 of the governor were of brass in diameter by thick mounted on flat spring steel 0.250 wide by 0.010" thick with the fastening screws on 3 /3" centers. Very little adjustment of the nut 83 on the take-up screw 82 was required for perfect calibra tion. It might be mentioned that ball bearings were used instead of the bushed bearings shown as a matter of convenience and that the workmanship was very good. It is apparent to those skilled in the art that the diameter of the spring, the number of coils, and the gauge of the wire may be altered yet produce the same results, and that changes in design and size together with workmanship had will alter the requirements. In order to obtain the smallest case 84 the spring 81 may be attached to the bottom of the lever 32, as shown in Fig. 1, by light broken lines, in which event the case 84' may carry the takeup screw 82 instead of the holder 85. It might be remarked at this point that it is very desirable to counterbalance the lever 32.

It was found that it required some force to overcome the initial tension or stiffness of the flat fly-ball governor springs 42 at low vehicle speeds. This force was also provided by the coil extension spring 81 and the thrust from said force was taken by the self-aligning bearing 22. The spring 81 must be designed to have sufficient tension at lower vehicle speeds and to slack off as the centrifugal force increases at higher vehicle speeds.

The force required to overcome the initial tension in the flat spring type of governor is not present in the direct lift type of centrifugal governor one modification of which is shown in Figs. 4 and 5.

This direct lift type of governor C uses the same shell 6 and its shaft 16 is identical with the shaft 16 used with the spring-operated governor D except for the position of the slot 39 therein. The shaft 16 is mounted in the same manner in both instances, connected to the flexible shaft drive 14 in the same manner, and connected to the lever 32 in the same manner. The difference lies'in the construction and operation of the governor C proper which includes a hub 86 secured to the shaft 16 by the set screw 87. Formed integral with the hub 86 is a face plate 88 provided on one face thereof with outstanding diametrically positioned jaws 89 for the hinge pins 90. These fly-ball weights 91 are formed as the frustum of a wedge relieved on the face 92 adjacent the shaft 16 to bring said face 92 in approximate alignment with the center of the shaft 16. This arrangement brings the inclined face 93 of the frustum adjacent the shell 6 whereby the weights 91 may have maximum outward movement. Each weight 91 has a tail piece 94 thru which the hinge pin 90 passes and upon which said weight is fulcrumed. The tail piece 94 terminates in a cam 95 disposed at right angles to but in alignment with the weight 91 and its tail piece 94. Slidably mounted on the shaft 16 is a sleeve 96 provided with a hub 97' adjacent the cam andadapted to be contacted by the end 95A thereof. 0n the opposite end of the sleeve 96 is another hub 98 in which is'a pin: 99 which passes thru said hub 98, the slot 39- in the shaft 16, and the end of the collared pin 23 slidably mounted. in the counterbore 24 formed in the end of the shaft 16. Also mounted on the shaft 16 is. a hub. 100 secured to said shaft by the set screw 101. Normally there is a dis.- tance of 0.28125" between the hubs 98 and 100 which is the maximum distance the hub 98 may be'moved by the centrifugal force of the weights 91. It will be. noted that the movement of the sliding hub 98 is. tov the right instead of to the left as in the spring-operated governor D, hence the 0 point of the lever 32 will be on the right instead of on left as shown in Figs. 1, 9, and 10. Such an arrangement permits the use of the calibrating coil extension spring 81 by which the switch contactor as 63 is brought into radial alignment with the radial edge. of the segment 53 which indicates a speed of 15 miles per hour when the vehicle is moving at a speed of 15 miles per hour.

The above described speed-indicator operating devices were among the equivalents enumerated in my application Ser. No. 117,457 which used as an example a means which used air pressure to operate the switch operating lever 32. In this application another form of this means. is described wherein said means may remain small in size and still furnish sufiicient pressure at speedometer speeds.

Figs. 9, 10, l1, and 12, show such a means'in the form of the Root blower. This device has a casing 102 with cover plates 103 and 104 provided with bosses, 105, 106, 107, and 108, bored to receive bushed bearings as 109 and 110. The boss 108 is longer than the others and has its end portion 108A threaded for the reception of the swivel nut 10 adapted to engage the annular collar 11 (see Fig. l) on the tail piece 12 compressed on the end of the flexible shaft casing 13 which surrounds the flexible drive shaft 14. When the swivel nut 10' has clamped the collar 11 against the boss 108 the core end 46 of the flexible drive shaft 14 is held in the counterbore 47 provided for its reception in the end of the shaft 111 and its key 48 in the keyway 49 of said shaft. The casing 102 is provided with a division wall 112 thus forming two chambers 113 and 114. The second shaft 115 like shaft 111 passes thru said division wall and is journalled in bearings carried in the bosses 105 and 106 while the shaft 111 is journalled in the bearings 109 and 110 in the bosses 107 and 108. In the chamber 113 on the shafts 111 and 115 are mounted similar spur gears 116 and 117 in meshing engagement, and in the chamber 114 on said shafts 111 and 115 are mounted similar pistons 118 and 119. These pistons 118 and 119 are not in contact with one another or with the casing 102 but have a slight clearance. The method of laying out the contours of the pistons is long and complicated and so those interested are referred to engineering handbooks such as Machinerys Encyclopedia.

In operation air enters the inlet opening 120 in the top of the casing'102 and is entrapped between the revolving pistons and the chamber walls and moved out thru the bottom discharge opening 121 into the chamber 122 which is closed on one end by the removable plug 123 and on the opposite end by the wall 124. Within this chamber 122 is a cylindrical piston 125 slidably mounted therein and provided with an elongated guide portion 126 which projects thru the end wall 124. The end 127 of the guide portion 126 is slotted to receive the lever 128 whose lower end is hingedly connected to the jaws 129 formed on the piston chamber casing 130 by the hinge pins 131. The piston 125, counterbored for lightness, has its closed end 125A provided with a boss 132 similar to the boss 133 formed on the end wall 124 for the support of a coil compression spring 134 provided for the return of the piston 125. To effect easy movement of the piston 125 the end wall 124 is provided with the bleed holes 135 for the egress of air entrapped between the piston 125 and the end wall 124. The lever 128 is hingedly connected to the guide portion 126 by the hinge pin 136, the lever being slotted to permit radial movement of the lever 128. The plug 123 has a longitudinal outlet 137 therethru into which a set screw 138 projects transversely. The pistons 118 and 119 deliver air into the chamber 122 creating a static pressure within said chamber 122 in accordance with the square of the speed of said pistons. This static pressure causes the piston 125 to move toward the closed end wall 124 against the tension in the open coil spring 134 in accordance with the pressure created. This pressure may be regulated by adjustment of the outlet opening 137 by the set screw 138. The static pressure within the chamber 122 need only be sufficient to move the piston 125 at all vehicle speeds for which the device is designed.

The pressure created by the pistons 118 and 119 at a speed of 250 R. P. M. should just be sufficient to move the piston 125 to move the lever 128 to bring the contacting balls 61 carried by said lever to the radial edge of the segment 53 which indicates a vehicle speed of 15 miles per hour after which no further adjustment is necessary for other vehicle speeds. The coil compression spring 134 within the chamber 122 may be replaced by a coil tension spring 139 provided with a take-up screw 140 and nut 141 as indicated by the light broken lines in Fig. 1.

Figs. 9 and 11, show the switch bases 57 attached to the ears 142 formed on the casing 162. Other than exact shape the switch bases 57 are similar in all three speedindicator operating devices described herein, and the switch-operating lever 128 corresponds to the switchoperating lever 32.

Attention is called to the fact that this invention admits of many modifications, arrangements, and equivalents without departing from the basic idea. Therefore, I do not limit my invention to any of the types of speed-indicator operating means nor to what I believe to be my preference at the moment, namely, the fly-ball type in one of its forms, but extend it to all that comes fairly within the scope of the appended claims.

What I claim as new over the prior art is:

1. In a speed-indicator operating device, the combination of a means having linear movement proportional to the square of the vehicle speed, a switch-operating lever operable thereby, and a plurality of switch segments of conducting material whose position and length have a relative relation to the square of the vehicle speed which are contactable by said lever.

2. In a speed indicator operating device for vehicles the combination of, a casing, a shaft journalled in said casing having a counterbore in one end, a drive for said shaft, a fly-ball governor mounted on the shaft, a hub movable thereby, a pin reciprocable in the shaft counterbore and attached to the movable hub, a lever adapted to be oscillated, a connection between the pin and the lever, a multiple circuit switch which includes a plurality of arcuate fixed contacts, a contact carried by the lever to engage the sequentially arranged fixed contacts, and a calibrating means to bring into synchronism the contact on the lever with a fixed contact.

3. In a speed indicator operating device for vehicles the combination of, a casing, a shaft journalled in said casing having a counterbore in one end, a drive for said shaft, a fiy-ball governor mounted on the shaft, a hub movable thereby, a pin reciprocable in the shaft counterbore and attached to the movable hub, a lever adapted to be oscillated, a self-aligning ball bearing having its inner race mounted on the pin and its outer race in a shell connected to the lever, a multiple circuit switch which includes a plurality of arcuate fixed contacts, a contact carried by the lever to engage the sequentially arranged fixed con tacts, and a calibrating means to bring into synchronism the contact on the lever with a fixed contact.

4. In a speed indicating means for a vehicle, a multiple circuit switch which includes a plurality of arcuate fixed contacts each representing a speed range said contacts being progressively arranged and having a common difference therebetween and a length proportional to the square of the highest speed represented in the series of speed ranges, a lever, a contact carried by the lever to engage the fixed contacts, and means to move the lever at a speed proportional to the square of the speed of the vehicle.

5. In a speed indicating means for a vehicle the combination of, a multiple circuit switch which includes a plurality of arcuate fixed contacts each representing a speed range and each progressively arranged with a predetermined common difference in the speed ranges and each having a length proportional to the square of the highest speed represented in the series of ranges, a lever having a contact to engage the fixed contacts, and means to move the lever at a speed proportional to the square of the speed of the vehicle.

6. In a speed indicating means for a vehicle the combination of, a multiple circuit switch which includes a plurality of arcuate fixed contacts each representing a speed range and each progressively arranged with a predetermined common difference in the speed ranges and each having a length proportional to the square of the highest speed represented in the series of ranges, a lever having a contact to engage the fixed contacts, means to move the lever at a speed proportional to the square of the speed of the vehicle, and means connected to said lever to align the contact thereon with a fixed contact representing a range of speed when the vehicle attains that speed.

7. In a speed indicating means for a vehicle having a plurality of switch segments, a lever, and means to bring the lever into contacting relation with the switch segments, a coil extension spring connected to the lever so as to have less tension as the vehicle speed increases, and means comprising an adjusting screw to align the lever with the edge of a switch segment representing a particular speed when the vehicle reaches that speed.

8. In a speed indicating means for a vehicle the combination of, a multiple circuit switch which includes a plurality of arcuate fixed contacts arranged in two oppositely disposed series each contact representing a speed range the contacts in one series representing half the speed range of those opposite to them in the other series those in the shorter speed range being spaced apart with the over-all length of both series being the same with each contact having a length proportional to the square of the highest speed common to both series of speed ranges, an oscillating lever having contact portions adapted to engage both series of fixed contacts at the same time to close two circuits at the same time when fixed contact portions are oppositely disposed, and means to move the lever at a speed proportional to the square of the speed of the vehicle.

References Cited in the file of this patent UNITED STATES PATENTS 956,635 Garbarino May 3, 1910 1,045,647 Wallace Nov. 26, 1912 1,098,358 Dean May 26, 1914 1,149,453 Landon Aug. 10, 1915 1,389,895 ONeil Sept. 6, 1921 1,485,197 OKeefe Feb. 26, 1924 1,785,618 Day Dec. 16, 1930 2,146,349 Provenzano Feb. 7, 1939 2,163,605 Kampa June 27, 1939 2,251,623 Crofoot et al. Aug. 5, 1941 2,478,690 Furnas et al. Aug. 9, 1949 

